The invention has to do with the construction of hollow domed structures, such as the igloo, which are used for human habitation and storage in areas abounding in ice and snow but which are sparsely provided with construction materials such as wood. Such structures have heretofore been made by sculpting snow or by making blocks of snow or ice and fitting them together in a cut-and-try process. Both methods are generally unsatisfactory and time consuming, and it has been the object of this invention to provide simple apparatus which may be easily carried and stored in a small space and which, without other apparatus or tools, may be used to build a complete domed structure. An additional object of the invention is to provide means to educate young adults in the construction of structures used for habitation from material supplied by nature.